JP2013505186A - Compositions and methods for producing lime sand bricks - Google Patents

Abstract

  The present invention relates to a composition for producing lime sand bricks comprising lime, sand, water and at least one plasticizer, in particular a comb having side chains connected to the main chain via ester or ether groups. It relates to the polymer KP. The invention further relates to a composition for producing lime sand bricks.

Description

  The present invention relates to the field of producing lime sand bricks.

  It has been known to produce so-called lime sand bricks from a mixture of lime, sand and water. The lime sand bricks have proven to be particularly effective in building buildings and have been accepted in this field. The characteristics of these lime sand bricks are high density and, due to them, their high heat storage capacity, static strength and their good sound insulation. In this method, a still moldable raw material consisting of sand, lime and water is pressed under high pressure under a hydraulic press to produce a green brick, and then under saturated vapor pressure at a temperature of 160-220 ° C. Curing in a steam curing autoclave. In this method, the chemical process in lime sand bricks is initiated by the hot steam atmosphere resulting in a strong interlock of sandstone bodies.

  According to the current state of the art, the molding pressure acting on the green lime sand brick is increased and / or the aggregate particle size distribution is optimized and / or the product quality, in particular the test bulk density and the compression Heavy aggregates, typically basalt, are added to increase strength.

  However, the applied molding pressure increases the wear of the pressing tool and increases energy consumption. The optimization of the particle size distribution can only be achieved by purchasing and transporting suitable sand further, which is a considerable economic disadvantage. This is because most lime sand brick manufacturers have company-owned sand mining grounds. Heavy aggregates such as basalt are disadvantageous in that they often have to be purchased further and are expensive.

  Furthermore, for lime sand bricks above a certain height, the forming pressure of the hydraulic press is no longer sufficient to provide sufficient press in the middle of the base brick, and the test bulk density of the final lime sand brick, And has a negative effect on compressive strength.

  Based on this, the object of the present invention is to provide a lime sand brick that has lower energy to press and results in higher product quality over the prior art.

  Surprisingly, it has been found that a composition for producing lime sand bricks comprising lime, sand, water and at least one plasticizer improves the processability of the composition in an uncured state. Plasticizers are typically used in cementitious compositions having a binder with a moisture content of 35-60% by weight, so typically only 1-10% by weight and temporarily up to 25% by weight moisture content. The improvement in processability in the composition for producing lime sand bricks having a slag is surprising.

  The composition of the present invention can achieve the desired test bulk density in the production of lime sand bricks with fewer press cycles, resulting in beneficial effects with respect to required energy, production time, and press tool wear. Is obtained. Furthermore, if the required molding pressure is reduced, less powerful and therefore less expensive presses and press dies can be used.

  Furthermore, it has surprisingly been found that increasing the plasticity of the composition according to the invention improves the bonding accuracy and allows more complex forms of the green press product.

  Furthermore, the composition according to the invention can reduce the amount of lime, and consequently increases the compressive strength and the test bulk density.

  As used herein, the term “bulk density being tested” is understood as the density of the green lime sand brick after pressing and hydrothermal treatment.

  Furthermore, even very large shaped bodies made from the composition according to the invention have a higher degree of compaction and thus a higher degree of compressive strength after pressing compared to conventional compositions. It was found to have.

  Furthermore, surprisingly, the additional use of surfactants reduces the required press cycle, resulting in a further improvement in the product quality of the lime sand bricks, ie the test bulk density and the compressive strength. I found.

  Other aspects of the invention are the subject of additional independent claims. Particularly preferred embodiments of the invention are the subject matter of the dependent claims.

  The present invention relates to a composition for producing lime sand bricks comprising lime, sand, water and at least one plasticizer.

  As used herein, the term “lime sand brick” refers to compressing, molding and curing (hydrothermal curing) under saturated vapor pressure, typically at a temperature of 160-220 ° C., for 4-12 hours. By means of a shaped body made from a mixture of lime and sand.

As used herein, the term “lime” is understood as calcium hydroxide (slaked lime, Ca (OH) ₂ ) typically obtained by an exothermic reaction between calcium oxide (quick lime, CaO) and water.

As used herein, the term “sand” is a round having a diameter of mainly 0.06 to 4 mm, separated from the original particle structure during mechanical and chemical collapse and transported to their deposition point. Or mineral clastic deposits (clastic rocks) which are loose agglomerates of loose particles (loose deposits), said deposits exceeding 50% by weight, in particular exceeding 75% by weight, particularly preferred Has a SiO ₂ content of more than 85% by weight.

  Typically, a suitable sand is a silica sand consisting of more than 85% by weight, in particular more than 90% by weight of quartz.

  As used herein, the term “plasticizer” is understood as an additive that improves the processability and flowability of mineral compositions, in particular compositions for producing lime sand bricks, or reduces the required moisture content. Is done.

  Suitable plasticizers are selected from the list consisting of lignin sulfonate, sulfonated melamine formaldehyde condensate, sulfonated naphthalene formaldehyde condensate, and comb polymer KP having side chains attached to the main chain via ester or ether groups. Plasticizer.

  Preferably, the at least one plasticizer is a comb polymer KP having side chains bonded to the main chain via ester or ether groups.

The comb polymer is composed of linear polymer chains (= main chains) having side chains bonded via ester groups or ether groups.
Figuratively speaking, the side chain forms the "tooth" of the "comb".

  Suitable comb polymers KP are on the one hand comb polymers having side chains which are connected to the linear polymer main chain via ether groups.

  The side chain bonded to the chain polymer main chain via an ether group can be introduced by polymerizing vinyl ether or allyl ether.

The comb polymer is disclosed, for example, in International Publication No. WO 2006/133933 A2, the contents of which are incorporated herein by reference. Vinyl ethers or allyl ethers have in particular the following formula (II):

  In the above formula, R ′ represents H, an aliphatic hydrocarbon moiety having 1 to 20 carbon atoms, an alicyclic hydrocarbon moiety having 5 to 8 carbon atoms, or 6 to 14 carbon atoms. Is an optionally substituted aryl moiety. R ″ is H or a methyl group and R ′ ″ is an unsubstituted or substituted aryl moiety, in particular a phenyl moiety.

  Furthermore, p is 0 or 1; m and n are each independently 2, 3 or 4; and x and y and z are independently 0 to 350.

  The arrangement of substructural elements designated as s5, s6 and s7 in formula (II) can be distributed alternately like blocks or randomly.

  In particular, this type of comb polymer is a copolymer of vinyl ether or allyl ether with maleic anhydride, maleic acid and / or (meth) acrylic acid.

  A suitable comb polymer KP is on the one hand a comb polymer having side chains bonded to the linear polymer main chain via ester groups. This type of comb polymer KP is preferred over a comb polymer having side chains attached to the linear polymer backbone through ether groups.

上記式中、Ｍは、互いに独立に、Ｈ^＋、アルカリ金属イオン、アルカリ土類金属イオン、二価又は三価金属イオン、アンモニウムイオン又は有機アンモニウム基である。本明細書では、用語「互いに独立に」とは、いずれの場合においても、同じ分子において、置換基が、様々な利用可能な意味を有し得ることを意味している。而して、例えば、式（Ｉ）のコポリマーは、同時にカルボン酸基及びカルボン酸ナトリウム基を包含することができ、そして、この場合では、Ｍは、互いに独立に、Ｈ^＋及びＮａ^＋を表していることを意味している。 Particularly preferred comb polymers KP are copolymers of formula (I).

In the above formula, M is independently of each other H ⁺ , an alkali metal ion, an alkaline earth metal ion, a divalent or trivalent metal ion, an ammonium ion, or an organic ammonium group. As used herein, the term “independent of each other” means that in any case, in the same molecule, the substituents can have a variety of available meanings. Thus, for example, the copolymer of formula (I) can simultaneously contain carboxylic acid groups and sodium carboxylate groups, and in this case, M independently of one another represents H ⁺ and Na ⁺ . It means that

  It will be apparent to those skilled in the art that, on the one hand, the copolymer is a carboxylate to which the ion M is bound, and on the other hand, the charge of the multivalent ion M must be compensated by the counter ion.

  Furthermore, the substituents R are, independently of one another, hydrogen or a methyl group.

Further, the substituents R ¹ are independently of each other-[AO] q-R ⁴ . The substituents R ² are independently of each other a C _{1 to} C ₂₀ alkyl group, a cycloalkyl group, an alkylaryl group, or — [AO] q—R ⁴ . In both cases, the substituent A is, independently of each other, a C ₂ -C ₄ alkylene group, R ⁴ is a C ₁ -C ₂₀ alkyl group, a cyclohexyl group or an alkylaryl group, and q is 2 It has a value of ~ 250, in particular 8 to 200, particularly preferably 11 to 150.

Furthermore, the substituent R ³ is independently —NH ₂ , —NR ⁵ R ⁶ , —OR ⁷ NR ⁸ R ⁹ . In the above formula, R ⁵ and R ⁶ are independently of each other a C ₁ -C ₂₀ alkyl group, a cycloalkyl group, an alkylaryl group, an aryl group, a hydroxyalkyl group, or acetoxyethyl (CH ₃ —CO—O—CH ₂ —CH ₂ ) or hydroxyisopropyl- (HO—CH (CH ₃ ) —CH ₂ ) or an acetoxyisopropyl group (CH ₃ —CO—O—CH (CH ₃ ) —CH ₂ —); or R ⁵ and R ⁶ Together form a ring, in which the nitrogen is one member that forms a morpholine or imidazoline ring.

The substituent R ⁷ is a C ₂ -C ₄ alkylene group.

Further, the substituents R ⁸ and R ⁹ are independently of each other a C _{1 to} C ₂₀ alkyl group, a cycloalkyl group, an alkylaryl group, an aryl group or a hydroxyalkyl group.

  The arrangement of substructure elements designated as s1, s2, s3 and s4 in formula (I) can be distributed alternately like blocks or randomly.

Finally, the subscripts a, b, c and d are the molar ratios of the structural units s1, s2, s3 and s4. These structural elements have the following ratios to each other:
a / b / c / d = (0.1−0.9) / (0.1−0.9) / (0−0.8) / (0−0.3),
In particular, a / b / c / d = (0.1−0.9) / (0.1−0.9) / (0−0.5) / (0−0.1),
Preferably a / b / c / d = (0.1−0.9) / (0.1−0.9) / (0−0.3) / (0−0.06)
However, a + b + c + d = 1. The sum of c + d is preferably greater than zero.

の対応モノマーのフリーラジカル重合によって製造できるか、
又は、他方では、下式（ＩＶ）

のポリカルボン酸のいわゆるポリマー類似反応によって製造できる。 The comb polymer KP of the formula (I), on the one hand, produces, on the one hand, the structural units s1, s2, s3 and s4 with the following formulas (IIIa), (IIIb), (IIIc) and (IIId)

Can be produced by free radical polymerization of the corresponding monomer of
Or, on the other hand, the following formula (IV)

The polycarboxylic acid can be produced by a so-called polymer-analogous reaction.

  In a polymer-analogous reaction, the polycarboxylic acid of formula (IV) is esterified or amidated with the corresponding alcohol or amine and then finally (according to the type of moiety M, for example with metal hydroxide or ammonia). ) Neutralized or partially neutralized. Details of the polymer-analogous reaction can be found, for example, in European Patent No. EP 1,138,697 B1, page 7, line 20 to page 8, line 50, and Examples, or European patent EP 1,061,089 B1, page 4. 54th line to 5th page 38th line and in the examples. In its refinement described in European Patent No. EP 1,348,729 A1 pages 3 to 5 and in the examples, the comb polymer KP of formula (I) can be produced in the solid state. The disclosures of the above patents are hereby incorporated by reference.

We have found that comb polymers KP of the formula (I) where c + d> 0, in particular d> 0, are a particularly preferred embodiment. In particular, it has been found that —NH—CH ₂ —CH ₂ —OH is a particularly advantageous R ³ moiety.

  Comb polymer KP, which is commercially available from Sika Schweiz AG under the trade name series ViscoCrete®, has been found to be particularly suitable.

  Furthermore, it is beneficial if the composition further comprises at least one surfactant.

  As used herein, the term “surfactant” is understood as a substance that reduces surface tension. However, the term “surfactant” does not include the plasticizers described above.

  Typically, surfactants are classified according to the type and charge of the hydrophilic molecular moiety. Four types of hydrophilic groups can be distinguished: anionic surfactants, cationic surfactants, nonionic surfactants and amphoteric surfactants.

Anionic surfactants typically have one or more functional anionic active groups that dissociate in water to ultimately form anions that are responsible for the surface active properties. Examples of typical surfactants groups: -COONa to produce _soap, a -SO ₃ Na, -OSO 3 Na, and, most important anionic surfactants include alkyl arene sulfonates (e.g., dodecylbenzene sulfonate) And alkane sulfonates, α-olefin sulfonates and alkyl sulfates, and alkyl sulfates.

Suitable anionic surfactants include higher alcohol sulfates such as lauryl sulfate or lauryl myristyl sulfate; ether sulfates; olefin / paraffin sulfonates; alkyl sulfonates; alkyl benzene sulfonates; sulfosuccinates such as dioctyl sulfosuccinates , Dilaures sulfosuccinate or C ₁₂ -C ₁₄ alcohol polyglycol ether sulfosuccinate; and phosphate esters.

  Cationic surfactants are almost exclusively characterized by the presence of quaternary ammonium groups. Of particular importance are cationic surfactants in which the nitrogen group is replaced by two long alkyl moieties and two short alkyl moieties, such as dimethyl distearyl ammonium chloride.

  Usually, nonionic surfactants are produced by ethoxylation of compounds having active hydrogen atoms; among them, addition products of ethylene oxide and aliphatic alcohols or oxo alcohols are the most important . In addition, ethoxylates of alkylphenols, alkylphenol polyglycol ethers, block polymers of ethylene oxide and propylene oxide (EO / PO block polymers), and alkyl glycosides are common.

  Suitable nonionic surfactants include, for example, alcohol ethoxylates marketed under the trademark Berol® 260 or Berol® 840; polyalkylene glycol ethers (also called aliphatic alcohol ethoxylates), such as poly Oxyethylene stearyl ether, polyoxyethylene lauryl ether or polyoxyethylene cetyl ether, some of which are marketed under the trademarks Brij®, Genapol® or Lutensol®; aliphatic Alcohol propoxylates; EO / PO block polymers such as Jeffox® WL-600; polypropylene glycols such as members of Pluriol® P; polyethylene groups Call; alkyl glucosides, for example Tween (R) 20; alkylpolyglycosides; octylphenol ethoxylates, for example Triton X-100; and nonylphenol ethoxylate is selected from the group consisting of, for example, from Nonoxinol-9.

  Preferred nonionic surfactants are nonionic surfactants selected from the group consisting of aliphatic alcohol ethoxylates and EO / PO block polymers.

  Particularly preferably, the at least one surfactant is a nonionic surfactant.

  Furthermore, the at least one surfactant is preferably a low foaming surfactant having a high wetting action. When released into wastewater by the cooling water of the autoclave, the foaming surfactant generates bubbles in the water body, for example, and thus can be a significant cause of environmental pollution even after wastewater treatment.

  The composition may include additional components. Preferably, the composition is typically 5-50% by weight, based on the total weight of the composition, and may further comprise aggregates, especially basalt. Examples of additional components are solvents or additives known in the lime sand brick technology, in particular preservatives, heat and light stabilizers, colorants and antifoaming agents.

  In preferred compositions, based on the total weight of the composition: the amount of sand is 60-96.5, in particular 80-94% by weight; the amount of lime is 3-15, in particular 4-10% by weight. The amount of water is 0.485-25, in particular 1-15, preferably 1-10% by weight; the amount of plasticizer is 0.015-0.5, preferably 0.018-0. And when present, the amount of surfactant is from 0.00003 to 0.1, in particular from 0.0003 to 0.015, preferably from 0.0003 to 0.009% by weight.

In another aspect, the invention provides the following steps:
i) providing the above composition which is a suitable and preferred composition;
ii) supplying the composition to at least one pressing device and pressing;
iii) It relates to a method for producing lime sand bricks comprising the step of curing the composition.

  Typically, the composition of step i) is provided by mixing sand, CaO, water, plasticizer and, if used, a surfactant.

The components are preferably mixed in a horizontal mixer, and the mixture is typically stored in a storage tank for a short time to convert most of the CaO to Ca (OH) ₂ . The composition thus obtained can then be pressed.

  Preferably, step i) provides a free-flowing material comprising sand, lime, water, plasticizer, and surfactant, if present, in an evenly dispersed form.

  For consolidation and / or molding, typically the equipment commonly used for hydraulic pressing can be used for pressing in step ii).

Preferably, the molding pressure applied is 10 to 25 N / mm ² , particularly preferably 15 to 20 N / mm ² .

  If desired, the composition can be formed into shaped bodies of any geometry, in particular blocks, bricks, L-shaped ceiling edge blocks for ceiling edge shunting, U-shaped opening blocks, Alternatively, it can be processed into a so-called vertical perforated brick. Furthermore, bricks typically have one of the usual formats from 1DF to 20DF according to DIN V 106. Preferably, a molded body having dimensions of 5 to 50 cm (length) x 5 to 50 cm (width) x 5 to 100 cm (height) is manufactured.

  Preferably, in step ii), shaped bodies are obtained that can be transported or stacked immediately after step ii) without losing or destroying their shape.

  The curing in step iii) is preferably a hydrothermal treatment carried out at a temperature of 160 to 220 ° C., in particular 180 to 200 ° C. under saturated vapor pressure. Curing typically takes 4 to 12 hours, especially 7 to 9 hours.

As used herein, the term “saturated vapor pressure” is understood as the pressure of the water vapor phase in a closed system in which the liquid and the water vapor phase are in equilibrium. During curing, the saturated vapor pressure is typically 10-16 bar. In step iii), a molded body having a compressive strength according to DIN V 106 of 12.5 to 35 N / mm ² is preferably obtained.

  Typically, the method is performed in the following order: step i), then step ii), then step iii).

The provided components of the composition are fed to the mixing device via at least one metering device and mixed;
The mixed components are fed into at least one pressing device and pressed;
A suitable embodiment is that the pressed composition is cured at a temperature of 160-220 ° C. under saturated vapor pressure.

  The method according to the present invention can dramatically reduce energy and time and press tool wear, and can also improve the product quality of the resulting lime sand bricks, especially the test bulk density and compressive strength.

  In another aspect, the invention relates to a solidified composition, in particular a shaped body, obtainable by the above method. In yet another aspect, the present invention relates to the use of the above composition for producing lime sand bricks.

Example
Additives used

Comparative examples V1-V6 and compositions Z1-Z8 according to the invention are provided by dry-mixing sand (and optionally basalt as heavy aggregate) and Ca (OH) ₂ with a Hobart mixer for 60 seconds did. Mixing water was added to the sand / Ca (OH) ₂ within 15 seconds and the mixture was mixed for 120 seconds. If an additive (ZM) is added, the additive is mixed with the mixing water for 120 seconds and then the mixing water is added to the sand / Ca (OH) ₂ mixture. Thereafter, the mixture was pressed.

In carrying out the examples, it was easier and faster to process by using Ca (OH) ₂ directly instead of CaO without converting CaO to Ca (OH) ₂ .

Example 1
Comparative Examples V1 to V3 and compositions Z1 to Z5 according to the invention, 53.5% by weight of sand, 35.9% by weight of basalt, 9% Prepared using 4 wt% Ca (OH) ₂ and 1.2 wt% water. The basalt used had a maximum particle size of 2 mm. When additives (see Table 2) were added to the entire composition, each weight percent of the additive was subtracted from the sand. Thus, when the additive used was 0.3% by weight, 53.2% by weight sand was used instead of 53.5% by weight. Sand, Ca (OH) ₂ , water, and optional additives were mixed as described above.

Mixtures of compositions according to the invention and comparative examples were pressed with a mechanical press to obtain test samples of 24 cm (length) x 11.5 cm (width) x 6 cm (height). The test sample was then cured in an autoclave under saturated vapor pressure. The test sample was then dried at 105 ° C., the test bulk density (kg / dm ³ units PRD) was calculated, and the compressive strength (N / mm ² units DF) of each test sample stacked to 2 1/2. )It was determined.

Table 2 shows that the composition according to the invention achieves a significantly higher compressive strength compared to the comparative example with the same test bulk density, and furthermore it is significantly better and more Suggests uniform compressibility.

Example 2
Comparative Examples V4 to V6 and the compositions Z8 to Z6 according to the invention are mixed with sand, Ca (OH) in the amount of weight% shown in Table 3, based on the total weight of the preparation composition according to the invention or the comparative examples. ₂ ) Prepared by using water, and optional additives. The sand is based on the total weight of the sand used, 20 wt% natural sand with a maximum particle size of 1 mm, 30.5 wt% natural sand with a maximum particle size of 3 mm, and a maximum particle size of 2 mm. It had 39.5% by weight of crushed sand. Mixing of sand, Ca (OH) ₂ and water and addition of optional additives was performed as described above.

  When the mixture of the composition according to the invention and the comparative example are pressed with a gyratory compactor (Gyratory Compactor ICT-100R available from Invelop Oy in Finland), a cylindrical test sample with a diameter of 100 mm is obtained. It was.

  The materials to be mixed were compressed and consolidated using a rotation angle of 40 mrad and a constant pressure of 4.5 bar. During this operation, the height of the test sample is measured for each cycle.

  This consolidation operation can be stopped after a certain rotation or when a certain sample height is reached. In the latter case, any bulk density can be adjusted by defining the amount and height of the material to be mixed. For a constant number of revolutions, the bulk density (bulk density before autoclaving) is calculated from the sample height achieved. The faster the mixture reaches the specified specimen height, the better the compressibility.

  The test sample was cured in an autoclave under saturated vapor pressure. Thereafter, the test samples were stored at 20 ° C. and 65% relative humidity and tested for compressive strength according to DIN 18501 (unpolished) at a load factor of 3.9 kN / s.

  As shown in Table 4, in the case of comparative examples V4 and V5 and compositions Z6 and Z7 according to the invention, when the specified sample height is reached, the compaction operation is stopped and the required rotation is carried out. confirmed.

From Table 4 it can be seen that the compositions according to the invention reach the specified bulk density in significantly fewer cycles.

  As shown in Table 5, in the case of Comparative Example V6 and the composition Z8 according to the invention, the consolidation operation was stopped after the specified 60 revolutions.

From Table 5 it can be seen that the composition according to the invention has a significantly higher test bulk density and compressive strength after the same number of cycles compared to the comparative example.

Claims (10)

  A composition for producing lime sand bricks comprising lime, sand, water and at least one plasticizer.   2. The composition according to claim 1, wherein the at least one plasticizer is a comb polymer KP having a side chain bonded to the main chain via an ester group or an ether group. The comb polymer KP has the following formula (I)

(Where
M is independently of each other H +, an alkali metal ion, an alkaline earth metal ion, a divalent or trivalent metal ion, an ammonium ion or an organic ammonium group;
Each R independently of the other moiety R of formula (I) is hydrogen or a methyl group;
R ¹ , independently of one another, is — [AO] q—R ⁴ ;
R ² is independently of each other a C ₁ -C ₂₀ alkyl group, a cycloalkyl group, an alkylaryl group, or — [AO] q—R ⁴ , wherein A is a C ₂ -C ₄ alkylene group, and R ⁴ is a C _{1 to} C ₂₀ alkyl group, a cyclohexyl group, or an alkylaryl group; and q = 2 to 250);
R ³ is independently of each other —NH ₂ , —NR ⁵ R ⁶ or —OR ⁷ NR ⁸ R ⁹ (wherein R ⁵ and R ⁶ are independently of each other a C _{1 to} C ₂₀ alkyl group, cycloalkyl A group, an alkylaryl group, or an aryl group;
Or a hydroxyalkyl group, acetoxyethyl (CH ₃ —CO—O—CH ₂ —CH ₂ ), hydroxyisopropyl (HO—CH (CH ₃ ) —CH ₂ ), or an acetoxyisopropyl group (CH ₃ —CO—O—); CH (CH ₃ ) —CH ₂ ), or R ⁵ and R ⁶ together form a ring in which the nitrogen is one member of forming a morpholine or imidazoline ring;
R ⁷ is a C ₂ -C ₄ alkylene group;
And the substituents R ⁸ and R ⁹ are each independently a C _{1 to} C ₂₀ alkyl group, a cycloalkyl group, an alkylaryl group, an aryl group, or a hydroxyalkyl group)
A, b, c and d are the molar ratios of the structural units s1, s2, s3 and s4;
And a / b / c / d, = (0.1-0.9) / (0.1-0.9) / (0-0.8) / (0-0.3), where A composition according to claim 2, characterized in that it is a copolymer of a + b + c + d = 1).   The composition according to any one of claims 1 to 3, wherein the composition further comprises at least one surfactant.   5. The composition of claim 4, wherein the at least one surfactant is a nonionic surfactant. Based on the total weight of the composition,
The amount of sand is 60-95.5% by weight;
The amount of lime is 3-15% by weight;
The amount of water is 0.485-25% by weight;
The amount of plasticizer is 0.015 to 0.5% by weight;
And, if present, the amount of the surfactant is 0.00003 to 0.1% by weight. The composition according to any one of claims 1 to 5, wherein The following steps:
i) providing a composition according to any one of claims 1-6;
ii) supplying and pressing the composition to at least one pressing device;
iii) A method for producing a lime sand brick comprising a step of curing the composition.   The method according to claim 7, wherein the curing is performed at a temperature of 160 to 220 ° C. under saturated vapor pressure.   The solidified composition obtained by the method as described in any one of Claim 7 or 8.   Use of the composition according to any one of claims 1 to 6 for producing lime sand bricks.